Symbol mapping for binary coding

ABSTRACT

The present disclosure presents symbol mapping for any desired error correction code (ECC) and/or uncoded modulation. A cross-shaped constellation is employed to perform symbol mapping. The cross-shaped constellation is generated from a rectangle-shaped constellation. Considering the rectangle-shaped constellation and its left hand side, a first constellation point subset located along that left hand side are moved to be along a top of the cross-shaped constellation while a second constellation point subset located along that left hand side are moved to be along a bottom of the cross-shaped constellation. For example, considering an embodiment having four constellation point subsets along the left hand side of the rectangle-shaped constellation, two of those subsets are moved to be along the top of the cross-shaped constellation while two other subsets of the constellation points along the left hand side are moved to be along the bottom of the cross-shaped constellation.

CROSS REFERENCE TO RELATED PATENTS/PATENT APPLICATIONS ProvisionalPriority Claims

The present U.S. Utility Patent Application claims priority pursuant to35 U.S.C. §119(e) to the following U.S. Provisional Patent Applicationswhich are hereby incorporated herein by reference in their entirety andmade part of the present U.S. Utility Patent Application for allpurposes:

1. U.S. Provisional Patent Application Ser. No. 61/658,746, entitled“Symbol mapping for binary coding,” filed Jun. 12, 2012.

2. U.S. Provisional Patent Application Ser. No. 61/818,485, entitled“Symbol mapping for binary coding,” filed May 2, 2013.

BACKGROUND

1. Technical Field

The present disclosure relates generally to communication systems; and,more particularly, to symbol mapping and/or symbol de-mapping (e.g.,modulation and/or demodulation) within various communication devicesoperative within such communication systems.

2. Description of Related Art

Data communication systems have been under continual development formany years. One such type of communication system that has been ofsignificant interest lately is a communication system that employsiterative error correction codes (ECCs). Communications systems withiterative codes are often able to achieve lower bit error rates (BER)than alternative codes for a given signal to noise ratio (SNR).

An ideal communication system design goal is to achieve Shannon's limitfor a communication channel. Shannon's limit may be viewed as being thedata rate to be used in a communication channel, having a particular SNRthat achieves error free transmission through the communication channel.In other words, the Shannon limit is the theoretical bound for channelcapacity for a given modulation and code rate.

Generally speaking, within the context of communication systems, thereis a first communication device at one end of a communication channelwith an ECC encoder and second communication device at the other end ofthe communication channel with an ECC decoder. In many instances, one orboth of these two communication devices includes both the encoder anddecoder (e.g., for bi-directional communications). The transmitter andreceiver may use various forms of symbol mapping and/or modulation togenerate symbols that carry more than one bit of information (e.g.,associated with constellation points of the symbol mapping and/ormodulation) to increase throughput of information within suchcommunication systems.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 illustrates an embodiment of a communication system.

FIG. 2 illustrates an example of communication between two communicationdevices.

FIG. 3 illustrates embodiments of encoding and symbol mapping and symbolde-mapping and decoding.

FIG. 4 illustrates an embodiment of conceptually altering a rectangleshaped constellation to achieve a cross shaped constellation.

FIG. 5 illustrates an example of 32 QAM constellation in accordance withthe present disclosure.

FIG. 6 illustrates an example of 128 QAM constellation in accordancewith the present disclosure.

FIG. 6A illustrates another example of a 128 QAM constellation inaccordance with the present disclosure.

FIG. 7 is a diagram illustrating an embodiment of a method for operatingone or more wireless communication devices.

FIG. 8 is a diagram illustrating another embodiment of a method foroperating one or more wireless communication devices.

DETAILED DESCRIPTION

FIG. 1 illustrates an embodiment of a communication system 100. Thecommunication system 100 that includes communication devices 110 120(only two shown) and communication system infrastructure, which supportsone or more wired or wireless communication channels 199. Thecommunication system infrastructure includes one or more of: a satellite130 and corresponding dishes 132, 134; a wireless communication link 140via wireless communication towers (e.g., base stations, access points,etc.) 142, 144 and/or an antennas 152, 154; fiber optic equipment suchas an optical communication link 160 via an electrical to optical (E/O)interface 162 and optical to electrical (O/E) interface 164; and a wiredcommunication link 150 (e.g., such as within a digital subscriber line(DSL) based system).

Each of the communication devices 110, 120 may be stationary or mobiledevices. For example, a mobile communication device 110 and 120 is oneof a cellular telephone, a tablet, a laptop computer, a video gameconsole, a remote controller, a multimedia (e.g., audio and/or video)player, etc. As another example, a stationary communication device is adevice that, while it can be moved, is generally used at a fixedlocation such as a computer, an access point, etc.

Each of the communication devices includes a transmitter 112, 126 and/ora receiver 116, 122. The transmitter 112, 126 includes an encoder 114,128 and the receiver 116, 122 includes a decoder 118, 124. The encoder114, 128 and the decoder 118, 124 utilize a constellation map thatincludes a plurality of constellation points and null points arranged inone or more patterns that reduce transmission errors and/or lower SNRwhile achieving a desired BER of a communication channel. Theconstellation map will be described in greater detail with reference toone or more of the subsequent figures.

FIG. 2 illustrates an example 200 of communication between twocommunication devices. In this example, the transmitter 112 of onecommunication device 110 is transmitting a signal via the communicationchannel 199 to the receiver 122 of another communication device 120. Thetransmitter 112 includes a processing module 280 a and a transmit driver230. The processing module 280 a is configured to include an encoder 222(e.g., low density parity check (LDPC) coding, any other desired errorcorrection code (ECC) such as turbo coding, convolutional coding, turbotrellis coded modulation (TTCM) coding, Reed-Solomon (RS) coding, BCH(Bose and Ray-Chaudhuri, and Hocquenghem) coding, etc. and/or uncodedmodulation) and a symbol mapper (SM) 224 or configured to include acombined encoder and symbol mapper 220. The transmit driver 230 includesa digital to analog converter (DAC) 232 and a transmit filter 234. Thereceiver 122 includes a processing module 280 b and an analog front end(AFE) 260. The processing module 280 b is configured to include adecoder 280 and a metric generator or symbol de-mapper 270. The AFE 260includes a receive filter 262 and an analog to digital converter (DAC)264.

In an example of operation, the encoder 222 of the transmitter 112receives information bits 201 of data (e.g., video data, audio data,text, graphics, voice data, etc.). The encoder 222 encodes (inaccordance with one or more ECC coding functions, FEC encodingfunctions, or other encoding functions) a number of the information bitsinto a plurality of encoded bits 202. For example, the encoder 222breaks the data into 4-bit data blocks and encodes each 4-bit data blockseparately to produce the plurality of encoded bits (e.g., an encodeddata block), which includes more bits than the data block (e.g., 5 ormore bits). As such, the encoder is outputting a sequence of encodedbits; one sequence for each data block.

The symbol mapper 224 maps the encoded bits (of one encoded data block)to a constellation point of a constellation map. The constellation mapincludes a plurality of constellation points and null points that arearranged to one or more patterns that reduce transmission errors and/orlower SNR while achieving a desired BER of a communication channel. Thesymbol mapper 224 outputs a sequence of symbols 203 (e.g., constellationpoints corresponding to mapped encoded data blocks) to the transmitdriver 230.

The DAC 232 converts the sequence of symbols into a continuous-timetransmit signal 204. The transmit filter 234 (e.g., channel filter,bandpass filter, notch filter, low pass filter, high pass filter, etc.)filters the signal 204 to produce a filtered, continuous-time transmit(TX) signal 205. The transmitter 112 transmits, via the communicationchannel 199, the filtered TX signal 205 to the receiver 112 of the othercommunication device 120.

Within the receiver 122, the receive filter 262 (e.g., channel filter,bandpass filter, notch filter, low pass filter, high pass filter, etc.)filters the continuous-time receive signal 206. An analog to digitalconverter (ADC) 264 converts the continuous-time receive signal 206 intodiscrete-time receive signals 208. The metric generator or symbolde-mapper 270 calculates metrics 209 (e.g., on either a symbol and/orbit basis, which may be log-likelihood ratios (LLRs) or other types ofmetrics). For example, metrics 209 may be viewed as estimatedconstellation points on the constellation map. The decoder 280 (whichessential performs the inverse of the encoder) interprets the metrics209 to create estimates of the information bits 210.

FIG. 3 illustrates embodiments 300 of encoding and symbol mapping andsymbol de-mapping and decoding. This diagram may be viewed as includingprocessing module 280 a and processing module 280 b such as may beimplemented in a communication device 110, 120 that includes both theencoding and decoding functions. In particular, the processing module280 is configured to include the encoder 222, the symbol mapper 224, themetric generator or symbol de-mapper 270, and the decoder 280. Thefunctions of these elements are as previously described. In additionalto the functionality as previously described, this embodiment provides abypass of the encoder 222 and the decoder 280. As such, for certainapplications, the information bits may be directly mapped toconstellation points on the constellation map.

Also, it is noted that any such desired modulation (e.g., constellationpoints with associated mapping/labeling of the constellation pointstherein) may be implemented in any of a variety of ways (e.g., look uptable (LUT) [such that a symbol of bit label is mapped to a respectiveconstellation point based on the LUT] in some form of memory, viareal-time calculation using one or more processors [such as a digitalsignal processor (DSP)], etc. and/or any such combination of means. Forexample, some embodiments will store the modulation in a LUT and/ormemory for relatively smaller sized constellations (e.g., includingconstellation points below some desired or predetermined value), and usereal-time calculation to generate the modulation for relatively largersized constellations (e.g., including constellation points equal to orabove some desired or predetermined value). For example, relativelylarge sized constellations can require a relatively significant amountof memory, and real-time calculation may be more efficient in someembodiments.

FIG. 4 illustrates an embodiment 400 of conceptually altering arectangle shaped constellation to achieve a cross shaped constellation.A conceptual rectangle-shaped constellation (e.g., one having more bitlocations along one particular axis then along the other) includessubsets of constellation points arranged in a rectangular pattern. Inthis example, the subsets include a common subset 402, a first subset404, a second subset 406, a third subset 408, and a fourth subset 410.The first and second subsets 404 and 406 are on the left side of therectangle shaped constellation map and the third and fourth subsets 408and 410 are on the right side of the rectangle shaped constellation map.Note that each subset of constellation points includes two or moreconstellation points and may be square shaped or rectangle shaped.

The conceptual rectangle shaped constellation is transformed into thecross-shaped constellation by rearranging some of the subsets. In thisexample, the common subset 402 is positioned similarly, with respect tofirst and second axis (e.g., an I axis and a Q axis) in the cross-shapedconstellation as it is in the rectangle shaped constellation. The firstsubset of the constellation points 404 is relocated from the left handside of the rectangle shaped constellation to the bottom of thecross-shaped constellation; the second subset of the constellationpoints 406 is relocated from the left hand side of the rectangle shapedconstellation to the top of the cross-shaped constellation; the thirdsubset of the constellation points 408 is relocated from the right handside of the rectangle shaped constellation to the top of thecross-shaped constellation; and the fourth subset of the constellationpoints 410 is relocated from the right hand side of the rectangle shapedconstellation to the top of the cross-shaped constellation.

As an alternative, the orientation of the conceptual rectangle shapedconstellation may be rotated ninety degrees such that there are moreconstellation points along the Q axis than the I axis. In thisalternative, the cross shaped constellation would be similarly rotated.

In one embodiment, a modification of the mapping performed in accordancewith the G.hn communication standard, specifically, Step 3 in Section7.1.4.3.1.2 Constellations for odd number of bits of Rec. ITU-T G.9960(December 2011), which includes the following formulas:|Q′|=|I|−2s, and sign(Q′)=sign(I);|I′|=M _(Q) −|Q|, and sign(I′)=sign(Q).

Modification of these respective formulas by their replacement asfollows:if (|Q|<2s) then|I′|=|I|−4s, and sign(I′)=sign(I);|Q′|=|Q|+4s, and sign(Q′)=sign(Q).else|I′|=M _(I) −|I|, and sign(I′)=sign(I);|Q′|=M _(I) −|Q|, and sign(Q′)=sign(Q).endif

will result in the modification of the rectangle-shaped constellation togenerate the cross-shaped constellation in accordance with variousembodiments and/or their equivalents herein.

In general, the conceptual conversion of a rectangle shapedconstellation into a shape as shown herein may be performed inaccordance with any desired symbols or bit labels having an odd numberof bits therein (e.g., 3, 5, 7, 9, 11, etc.). For example, a givensymbol or bit label can include an odd number of encoded bits, N, whereN is an odd-valued integer, and the modulation can would then includeY=2^(N) constellation points (e.g., if N=5, then Y=32; if N=7, thenY=128; etc.).

FIG. 5 illustrates an example 500 of 32 QAM constellation map (or justconstellation) in accordance with the present disclosure. Theconstellation includes a plurality of constellation points and nullpoints at the corners (e.g., a null may be viewed as a location thatdoes not include a constellation point). FIG. 5 further illustrates aconceptual rectangle shaped constellation that includes four rows andeight columns centered about the origin of the intersection of a firstand second axis. The axis forms quadrants; each quadrant including eightconstellation points.

The conceptual rectangle shaped constellation includes a common subsetof constellation points, a first subset of constellation points, asecond subset of constellation points, a third subset of constellationpoints, and a fourth subset of constellation points. The first subsetincludes constellation points corresponding symbols 01 000 and 11 000;the second subset includes constellation points corresponding to symbols10 000 and 00 000; the third subset includes constellation pointscorresponding to symbols 01 001 and 11 001; the fourth subset includesconstellation points corresponding to symbols 10 001 and 00 001; thecommon subset includes the remaining constellation points.

The conceptual rectangle shaped constellation is conceptually modifiedto the desired constellation by moving the first, second, third, andfourth subsets of constellation points as shown. The resultingconstellation has a cross shape with null points in the corners. Ineffect, by relocating constellation points of a conceptual rectangleshaped constellation into the desired shape, the collective magnitude ofthe vector of the relocated constellation points is less than thecollective magnitudes of the vectors if not relocated. Further, the newpattern maintains a one-bit difference between symbols of vertical andhorizontal adjacent constellation points.

The new pattern of the constellation also has symmetry about the axis.For example, the pattern of constellation points and null points of thefirst quadrant (e.g., upper left quadrant on the figure) is the mirrorimage about the vertical axis as the pattern of constellation points andnull points of the second quadrant (e.g., the upper right quadrant onthe figure). In this example, the first quadrant also a mirrored patternof constellation points and null points, about the horizontal axis, asthe pattern of the third quadrant (e.g., the lower left quadrant of thefigure). As a further example, the second quadrant has a mirroredpattern of constellation points and null points, about the horizontalaxis, as the pattern of the fourth quadrant (e.g., the lower rightquadrant of the figure).

FIG. 6 illustrates an example 600 of 128 QAM constellation in accordancewith the present disclosure. In this example, the constellation includes128 constellation points (one for each symbol in the range of 0 to 2⁸)and sixteen null points. The concept of modifying a rectangle shapedconstellation into the present constellation is the same as discussedwith reference to FIGS. 4 and 5, with a difference being the number ofconstellation points in a subset. In this example, the first subsetincludes eight constellation points (111 0000, 111 1000, 101 1000, 101000, 011 0000, 011 1000, 001 1000, and 001 0000), and so on.

The 128 QAM constellation has a cross shaped pattern of constellationpoints with null points in the corners and, by relocating constellationpoints of a conceptual rectangle shaped constellation into the desiredshape, the magnitude of the vector of the relocated constellation pointsis most often less than the magnitude of the vector if not relocated.Further, the new pattern maintains a one-bit difference between symbolsof vertical and horizontal adjacent constellation points and hassymmetry from quadrant to quadrant about the vertical and/or horizontalaxis.

FIG. 6A illustrates another example 601 of a 128 QAM constellation inaccordance with the present disclosure. In this example, theconstellation includes 128 constellation points (one for each symbol inthe range of 0 to 2⁸), a plurality of null points, and the modificationof the conceptual rectangle shaped constellation is somewhat different.As with FIG. 6, the conceptual rectangle shaped constellation includesthe first, second, third, fourth, and common subsets of constellationpoints. In this example, however, the first, second, third, and fourthsubsets are relocated differently.

In particular, the subsets are relocated to maintain the 1 bitdifference between symbols of horizontally and vertically adjacentconstellation points and collectively reduce the magnitude of the vectorfor the relocated constellation points with respect to the rectangleshaped constellation. For example, the constellation points of the firstsubset 404 are relocated as shown. In a particular example,constellation point corresponding to symbol 111 1000 is shown in row 6,column 3 of quadrant 1 (from the origin) in FIG. 6 and is shown in row7, column 2 of quadrant 1 in FIG. 6A. Further, the constellation pointcorresponding to symbol 111 0000 is shown in row 6, column 4 of quadrant1 of FIG. 6 and in row 7, column 1 of quadrant 1 of FIG. 6A. Note thatthere are 17 null points in each of the four corners of a square outlineencompassing the 128 QAM constellation.

FIG. 7 is a diagram illustrating an embodiment of a method 700 foroperating one or more wireless communication devices. One implementationof the method 700 operates by performing only the operations of theblocks 710 and 720. Another implementation of the method 700 operates byperforming only the operations of the blocks 710, 720, and 722. Yetanother implementation of the method 700 operates by performingoperations of all of the blocks therein.

Referring to the diagram, the method 700 begins by encoding at least oneinformation bit to generate at least one encoded bit, as shown in ablock 710.

The method 700 continues by operating a symbol mapper (e.g., ofcommunication device) to map at least one symbol or bit label includingthe at least one encoded bit to a cross-shaped constellation, as shownin a block 720.

With respect to the cross-shaped constellation employed, it may beviewed as being derived from a rectangle-shaped constellation. Forexample, the cross-shaped constellation derived from a rectangle-shapedconstellation having a plurality of constellation points includingsubsets of the plurality of constellation points along either a lefthand side or a right hand side of the rectangle-shaped constellationsuch that a first of the subsets of the plurality of constellationpoints relocated to be along a top of the cross-shaped constellation anda second of the subsets of the plurality of constellation pointsrelocated to be along a bottom of the cross-shaped constellation, asshown in a block 722. This transformation may alternatively be viewed asgenerating a constellation that includes a plurality of constellationpoints and a set of null points orientated with respect to at least oneof a first axis and a second axis, and such that quadrants of theconstellation, from quadrant to quadrant along at least one of the firstaxis and the second axis, have a mirroring pattern of constellationpoints of the plurality of constellation points and of null points ofthe set of null points.

In certain embodiments, the method 700 then operates by operating atransmit driver of the communication device to process at least onediscrete-valued modulation symbol (e.g., generated by the symbol mapper)to generate a continuous-time signal, as shown in a block 730.

Also, in certain embodiments, the method 700 continues by transmittingthe continuous-time signal to at least one additional communicationdevice via at least one communication channel, as shown in a block 740.

FIG. 8 is a diagram illustrating another embodiment of a method 800 foroperating one or more wireless communication devices. Referring tomethod 800 of FIG. 8, one implementation of the method 800 operates byperforming only the operations of the blocks 830 and 840. Anotherimplementation of the method 800 operates by performing only theoperations of the blocks 830, 832, and 840. Yet another implementationof the method 800 operates by performing operations of all of the blockstherein.

Referring to the diagram, the method 800 begins by receiving acontinuous-time signal from at least one additional communication devicevia at least one communication channel (e.g., via at least one inputand/or communication interface of a communication device), as shown in ablock 810.

The method 800 continues by operating an analog front end (AFE) of thecommunication device to process the continuous-time signal to generate adiscrete-time signal, as shown in a block 820.

The method 800 then operates by operating a symbol de-mapper of thecommunication device to process the discrete-time signal based on across-shaped constellation (e.g., to generate symbol and/or bitmetrics), as shown in a block 830.

With respect to the cross-shaped constellation employed, it may beviewed as being derived from a rectangle-shaped constellation. Forexample, the cross-shaped constellation derived from a rectangle-shapedconstellation having a plurality of constellation points includingsubsets of the plurality of constellation points along either a lefthand side or a right hand side of the rectangle-shaped constellationsuch that a first of the subsets of the plurality of constellationpoints relocated to be along a top of the cross-shaped constellation anda second of the subsets of the plurality of constellation pointsrelocated to be along a bottom of the cross-shaped constellation, asshown in a block 832.

The method 800 continues by performing decoding processing based on thesymbol and/or bit metrics to generate at least one estimate of aninformation bit encoded within the continuous-time signal, as shown in ablock 840.

The present invention has been described herein with reference to atleast one embodiment. Such embodiment(s) of the present invention havebeen described with the aid of structural components illustratingphysical and/or logical components and with the aid of method stepsillustrating the performance of specified functions and relationshipsthereof. The boundaries and sequence of these functional building blocksand method steps have been arbitrarily defined herein for convenience ofdescription. Alternate boundaries and sequences can be defined so longas the specified functions and relationships are appropriatelyperformed. Any such alternate boundaries or sequences are thus withinthe scope and spirit of the claims that follow. Further, the boundariesof these functional building blocks have been arbitrarily defined forconvenience of description. Alternate boundaries could be defined aslong as the certain significant functions are appropriately performed.Similarly, flow diagram blocks may also have been arbitrarily definedherein to illustrate certain significant functionality. To the extentused, the flow diagram block boundaries and sequence could have beendefined otherwise and still perform the certain significantfunctionality. Such alternate definitions of both functional buildingblocks and flow diagram blocks and sequences are thus within the scopeand spirit of the claimed invention. One of average skill in the artwill also recognize that the functional building blocks, and otherillustrative blocks, modules and components herein, can be implementedas illustrated or by discrete components, application specificintegrated circuits, processors executing appropriate software and thelike or any combination thereof.

As may also be used herein, the terms “processing module,” “processingcircuit,” “processing circuitry,” and/or “processing unit” may be asingle processing device or a plurality of processing devices. Such aprocessing device may be a microprocessor, micro-controller, digitalsignal processor, microcomputer, central processing unit, fieldprogrammable gate array, programmable logic device, state machine, logiccircuitry, analog circuitry, digital circuitry, and/or any device thatmanipulates signals (analog and/or digital) based on hard coding of thecircuitry and/or operational instructions. The processing module,module, processing circuit, and/or processing unit may be, or furtherinclude, memory and/or an integrated memory element, which may be asingle memory device, a plurality of memory devices, and/or embeddedcircuitry of another processing module, module, processing circuit,and/or processing unit. Such a memory device may be a read-only memory,random access memory, volatile memory, non-volatile memory, staticmemory, dynamic memory, flash memory, cache memory, and/or any devicethat stores digital information. Note that if the processing module,module, processing circuit, and/or processing unit includes more thanone processing device, the processing devices may be centrally located(e.g., directly coupled together via a wired and/or wireless busstructure) or may be distributedly located (e.g., cloud computing viaindirect coupling via a local area network and/or a wide area network).Further note that if the processing module, module, processing circuit,and/or processing unit implements one or more of its functions via astate machine, analog circuitry, digital circuitry, and/or logiccircuitry, the memory and/or memory element storing the correspondingoperational instructions may be embedded within, or external to, thecircuitry comprising the state machine, analog circuitry, digitalcircuitry, and/or logic circuitry. Still further note that, the memoryelement may store, and the processing module, module, processingcircuit, and/or processing unit executes, hard coded and/or operationalinstructions corresponding to at least some of the steps and/orfunctions illustrated in one or more of the Figures. Such a memorydevice or memory element can be included in an article of manufacture.

As may be used herein, the terms “substantially” and “approximately”provides an industry-accepted tolerance for its corresponding termand/or relativity between items. Such an industry-accepted toleranceranges from less than one percent to fifty percent and corresponds to,but is not limited to, component values, integrated circuit processvariations, temperature variations, rise and fall times, and/or thermalnoise. Such relativity between items ranges from a difference of a fewpercent to magnitude differences. As may also be used herein, theterm(s) “configured to”, “operably coupled to”, “coupled to”, and/or“coupling” includes direct coupling between items and/or indirectcoupling between items via an intervening item (e.g., an item includes,but is not limited to, a component, an element, a circuit, and/or amodule) where, for an example of indirect coupling, the intervening itemdoes not modify the information of a signal but may adjust its currentlevel, voltage level, and/or power level. As may further be used herein,inferred coupling (i.e., where one element is coupled to another elementby inference) includes direct and indirect coupling between two items inthe same manner as “coupled to”. As may even further be used herein, theterm “configured to”, “operable to”, “coupled to”, or “operably coupledto” indicates that an item includes one or more of power connections,input(s), output(s), etc., to perform, when activated, one or more itscorresponding functions and may further include inferred coupling to oneor more other items. As may still further be used herein, the term“associated with”, includes direct and/or indirect coupling of separateitems and/or one item being embedded within another item.

Unless specifically stated to the contra, signals to, from, and/orbetween elements in a figure of any of the figures presented herein maybe analog or digital, continuous time or discrete time, and single-endedor differential. For instance, if a signal path is shown as asingle-ended path, it also represents a differential signal path.Similarly, if a signal path is shown as a differential path, it alsorepresents a single-ended signal path. While one or more particulararchitectures are described herein, other architectures can likewise beimplemented that use one or more data buses not expressly shown, directconnectivity between elements, and/or indirect coupling between otherelements as recognized by one of average skill in the art.

The term “module” is used in the description of one or more of theembodiments. A module includes a processing module, a functional block,hardware, and/or software stored on memory for performing one or morefunctions as may be described herein. Note that, if the module isimplemented via hardware, the hardware may operate independently and/orin conjunction with software and/or firmware. As also used herein, amodule may contain one or more sub-modules, each of which may be one ormore modules.

While particular combinations of various functions and features of theone or more embodiments have been expressly described herein, othercombinations of these features and functions are likewise possible. Thepresent disclosure of an invention is not limited by the particularexamples disclosed herein and expressly incorporates these othercombinations.

What is claimed is:
 1. A communication device comprising: an encoderconfigured to encode at least one information bit to generate aplurality of encoded bits; and a symbol mapper configured to map theplurality of encoded bits to a constellation point of a constellation,wherein the constellation includes a plurality of constellation pointsand a set of null points orientated with respect to at least one of afirst axis or a second axis, wherein quadrants of the constellation,from quadrant to quadrant along at least one of the first axis or thesecond axis, have a mirroring pattern of constellation points of theplurality of constellation points and of null points of the set of nullpoints, and wherein the set of null points corresponds to a plurality oflocations in the constellation not including constellation points. 2.The communication device of claim 1, wherein the plurality of encodedbits comprises: an odd number of encoded bits, N, where N is anodd-valued integer; and the plurality of constellation points includes2^(N) constellation points.
 3. The communication device of claim 1,wherein the constellation comprises: along the first axis or along thesecond axis, an adjacent constellation point of the constellationrepresents a one-bit difference of encoded bits with respect to theplurality of encoded bits.
 4. The communication device of claim 1further comprising: a transmit driver configured to transmit acontinuous-time signal that is representative of at least one of theplurality of constellation points.
 5. The communication device of claim1 further comprising a transmitter and a receiver for communicationwithin at least one of a satellite communication system, a wirelesscommunication system, a wired communication system, a fiber-opticcommunication system, or a mobile communication system.
 6. Acommunication device comprising: an encoder configured to encode atleast one information bit to generate at least one encoded bit; and asymbol mapper configured to map at least one symbol or bit label that isrepresentative of the at least one encoded bit to a constellation pointof a cross-shaped constellation, wherein the cross-shaped constellationis based on a rectangle-shaped constellation having a plurality ofconstellation points that includes subsets of the plurality ofconstellation points along at least one of a left hand side or a righthand side of the rectangle-shaped constellation, wherein a first subsetof the subsets of the plurality of constellation points is relocated toa top of the cross-shaped constellation and a second subset of thesubsets of the plurality of constellation points is relocated to abottom of the cross-shaped constellation.
 7. The communication device ofclaim 6, wherein: the first and second subsets being on the left handside of the rectangle-shaped constellation; and the right hand side ofthe rectangle-shaped constellation including a third subset and a fourthsubset of the subsets of the plurality of constellation points, whereinthe at least one additional subsets of the plurality of constellationpoints, such that: the third subset is relocated to the top of thecross-shaped constellation; and the fourth subset is relocated to thebottom of the cross-shaped constellation.
 8. The communication device ofclaim 6, wherein the encoder comprising a low density parity check(LDPC) code encoder.
 9. The communication device of claim 6, wherein theat least one symbol or bit label comprising: an odd number of encodedbits, N, where N is an odd-valued integer; and the plurality ofconstellation points includes 2^(N) constellation points.
 10. Thecommunication devices of claim 6, wherein the rectangle-shapedconstellation further comprising at least one additional subset ofconstellation points, located between the left hand side or the righthand side of the rectangle-shaped constellation, that are also includedand commonly located within the cross-shaped constellation.
 11. Thecommunication device of claim 6 further comprising: a transmit driverconfigured to transmit a continuous-time signal that is representativeof the constellation point.
 12. The communication device of claim 6further comprising: an input configured to receive a continuous-timesignal that represents a transmitted constellation point; an analogfront end (AFE) configured to process the continuous-time signal togenerate a discrete-time signal; and a symbol de-mapper configured toprocess the discrete-time signal based on the cross-shaped constellationto identify the transmitted constellation point.
 13. The communicationdevice of claim 6 further comprising: a transmitter and receiver forcommunication within at least one of a satellite communication system, awireless communication system, a wired communication system, afiber-optic communication system, or a mobile communication system. 14.A method for execution by a communication device, the method comprising:encoding at least one information bit to generate at least one encodedbit; and operating a symbol mapper of the communication device to map atleast one symbol or bit label that includes the at least one encoded bitto a constellation, wherein the constellation includes a plurality ofconstellation points and a set of null points orientated with respect toat least one of a first axis or a second axis, wherein quadrants of theconstellation, from quadrant to quadrant along at least one of the firstaxis or the second axis, have a mirroring pattern of constellationpoints of the plurality of constellation points and of null points ofthe set of null points, and wherein the set of null points correspondsto a plurality of locations in the constellation that not includingconstellation points.
 15. The method of claim 14, wherein: theconstellation is a cross-shaped constellation that is based on arectangle-shaped constellation having the plurality of constellationpoints, wherein the plurality of constellation points includes subsetsof the plurality of constellation points along at least one of a lefthand side or a right hand side of the rectangle-shaped constellation,wherein a first subset of the subsets of the plurality of constellationpoints is relocated to a top of the cross-shaped constellation and asecond subset of the subsets of the plurality of constellation points isrelocated to a bottom of the cross-shaped constellation; the first andsecond subsets being on the left hand side of the rectangle-shapedconstellation; and the right hand side of the rectangle-shapedconstellation including a third subset and a fourth subset of thesubsets of the plurality of constellation points, wherein the at leastone additional subsets of the plurality of constellation points, suchthat: the third subset is relocated to the top of the cross-shapedconstellation; and the fourth subset is relocated to the bottom of thecross-shaped constellation.
 16. The method of claim 14 furthercomprising: performing low density parity check (LDPC) code encoding toencode the at least one information bit to generate an LDPC codewordthat includes the at least one encoded bit.
 17. The method of claim 14,wherein the at least one symbol or bit label comprising: an odd numberof encoded bits, N, where N is an odd-valued integer; and the pluralityof constellation points includes 2^(N) constellation points.
 18. Themethod of claim 14, wherein: the constellation is a cross-shapedconstellation that is based on a rectangle-shaped constellation havingthe plurality of constellation points; the plurality of constellationpoints includes subsets of the plurality of constellation points alongat least one of a left hand side or a right hand side of therectangle-shaped constellation; and the rectangle-shaped constellationfurther comprising at least one additional subset of constellationpoints, located between the left hand side or the right hand side of therectangle-shaped constellation, that are also included and commonlylocated within the cross-shaped constellation.
 19. The method of claim14 further comprising: transmitting a continuous-time signal that isrepresentative of at least one of the plurality of constellation points.20. The method of claim 14, wherein the communication device isoperative within at least one of a satellite communication system, awireless communication system, a wired communication system, afiber-optic communication system, and or a mobile communication system.